1. Field of the Invention
The present invention relates to a pixel structure of an organic light emitting display device and more particularly, to a pixel structure where allocations of the sub-pixels are modified for lowering demands on precisions of masks and enhancing manufacturing process stability of the pixel structure.
2. Description of the Prior Art
Organic light emitting diode displays, which have the advantages of absence of color filter, self-luminescence and low power consumption, is always viewed as the best candidate to substitute for the liquid crystal display and become the main display technology of the next generation.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic diagram illustrating a conventional organic light emitting diode display device. FIG. 2 is a schematic diagram illustrating a mask used for manufacturing the conventional organic electroluminescent display device. As shown in FIG. 1 and FIG. 2, a mask 100M including stripe openings 100H extending along a column direction Y is used in an evaporation process of organic light emitting materials for manufacturing a pixel structure 100 of a conventional organic light emitting display device. A plurality of blue sub-pixels 120B, a plurality of green sub-pixels 120G and a plurality of red sub-pixels 120R are formed on a substrate 110 by the evaporation process. Each of the blue sub-pixels 120B, each of the green sub-pixels 120G and each of the red sub-pixels 120R are alternately disposed along a row direction X. A display pixel unit 120 is composed of a blue sub-pixel 120B, a green sub-pixel 120G and a red sub-pixel 120R disposed adjacently along the row direction X. This is so-called a stripe type pixel arrangement. In this pixel structure, a specific distance between the stripe openings 100H is required for maintaining sufficient structural strength of the mask 100M to avoid yield loss of the pixel structure 100 caused by process variations and low aligning precision of the manufacturing process. However, the distance between the stripe openings 100H has to be shrunk for higher resolution demand about the pixel structure. Problems such as complicated manufacturing process of the masks and worse stability of the organic light emitting material may become serious accordingly.